Training Grant in Population Neuroscience of Aging & Alzheimer?s Disease (PNA) The objective of this new pre- and post-doctoral training program is to train highly talented individuals to pursue successful independent research in the etiology of Alzheimer?s Disease and other age-related dementia (ADRD). Eligible applicants are PhD graduates or candidates in Epidemiology, Neuroscience, Information Science, Biostatistics, Biomedical informatics and MD/DO graduates with training in Neurology, Psychiatry, Geriatric medicine, and related disciplines. We request support for 3 pre-doctoral and 2 post-doctoral positions annually, with a period of training of up to 3 years for post-docs and 4 years for pre-docs (up to 5 in some cases). The field of brain aging has profoundly changed because of the collision of two phenomena: worldwide increase of our aging population, and rapid technological advancements in health measurements in general and in brain science in particular. Our successes in extending lifespan, with marginal improvements in healthspan, have not only increased the number of adults reaching very old ages, but they have also increased the heterogeneity of age-related neurocognitive phenotypes. For these ?new? older adults, there is a very high burden of chronic conditions affecting the central nervous system either directly (e.g. stroke) or indirectly (heart conditions, diabetes). Cumulative exposure to chronic conditions, biological ageing, chronological aging and possibly to other life-long environmental factors, interact with each other in very complex ways and are all strong drivers of increased risks of developing dementia. While it is reasonable to expect brain integrity to decline and dementia rates to increase over time, we cannot assume that chronological years and years spent with a disease would have linearly additive effects on brain integrity. Understanding these complex pathways is fundamentally important to conduct rigorous etiological research into causes and determinants of brain degeneration and dementia. Unfortunately, training and research in the field to date have focused on dementia as an individual condition, and have mostly considered ?older age? as an homogenous population, while relegating multiple chronic conditions and other health issues as ?collateral problems?, or as completely separate problems. However, it is clear that to understand these complex issues and improve the brain health of the growing population of elderly living with chronic diseases for a long time, it is necessary to have expertise in diseases of both the brain/central nervous system and also other organ systems. We are also living through a time of great technological advances in non-invasive and automated methods to measure brain abnormalities, the application of which is providing ever more precise phenotypes but also very large and complex datasets. Such data require careful sampling designs and analytical approaches infused with an understanding of the condition being studied to effectively produce new knowledge to move research to treatment and prevention. We propose that the successful clinical neuroepidemiological investigators of the future must be able to link comorbidities, environmental exposures, lifestyles, genomics, e.g. host susceptibility, with knowledge of modern technology of neurosciences and measurement of brain disease and data science. Our proposed T32 in Population Neuroscience of Aging & Alzheimer?s Disease (PNA) merges this gap and aims to cross-train researchers in these inter-related fields. Co-directors Drs. Rosano (Epidemiology) and Ganguli (Psychiatry) have designed a new training formula that benefits from the extensive resources and faculty affiliated with the Schools of Public Health (Biostatistics), Medicine (Neurology, Biomedical Informatics), Arts and Science (Neuroscience, Psychology), and Information Science, as well as several University Centers and Institutes: the Alzheimer Disease Research Center, the Center for the Neural Basis of Cognition, the Brain Institute, the Center for Aging, Population and Health, the Claude Pepper, the Aging Institute. Our curriculum responds to the changing landscape of career pathways, by including: a) foundational knowledge in data science; b) availability of multi-center and international databases; c) enhanced training in cutting-edge multimodal methodologies to measure brain changes with age, including neuroimaging and post-mortem assessments; d) hands-on experiences with internet-based designs for recruitment and data collection. Training in the responsible conduct of research and efforts to increase diversity are important objectives of the program.